be self-sustaining. Too large a charge simply
rekindles the original vortex--still larger--in its original crater. And
the activity that must be matched varies so tremendously, in magnitude,
maxima, and minima, and the cycle is so erratic--ranging from seconds to
hours without discoverable rhyme or reason--that all attempts to do so
at any predetermined instant have failed completely. Why, even Kinnison
and Cardynge and the Conference of Scientists couldn't solve it, any
more than they could work out a tractor beam that could be used as a
tow-line on one."

"Not exactly," Cloud demurred. "They found that it could be forecast,
for a few seconds at least--length of time directly proportional to the
length of the cycle in question--by an extension of the calculus of
warped surfaces."

"Humph!" the Lensman snorted. "So what? What good is a ten-second
forecast when it takes a calculating machine an hour to solve the
equations.... Oh!" He broke off, staring.

"Oh," he repeated, slowly, "I forgot that you're a lightning
calculator--a mathematical prodigy from the day you were born--who never
has to use a calculating machine even to compute an orbit.... But there
are other things."

"I'll say there are; plenty of them. I'd thought of the calculator angle
before, of course, but there was a worse thing than variability to
contend with...."

"What?" the Lensman demanded.

"Fear," Cloud replied, crisply. "At the thought of a hand-to-hand battle
with a vortex my brain froze solid. Fear--the sheer, stark, natural
human fear of death, that robs a man of the fine edge of control and
brings on the very death that he is trying so hard to avoid. That's what
had me stopped."

"Right ... you may be right," the Lensman pondered, his fingers drumming
quietly upon his desk. "And you are not afraid of death--now--even
subconsciously. But tell me, Storm, please, that you won't invite it."

"I will not invite it, sir, now that I've got a job to do. But that's as
far as I'll go in promising. I won't make any superhuman effort to avoid
it. I'll take all due precautions, for the sake of the job, but if it
gets me, what the hell? The quicker it does, the better--the sooner I'll
be with Jo."

"You believe that?"

"Implicitly."

"The vortices are as good as gone, then. They haven't got any more
chance than Boskone has of licking the Patrol."

"I'm afraid so," almost glumly. "The only way for it to get me is for me
to make a mistake, an